Bioimpedance Parameter Estimation using Fast Spectral Measurements and Regularization

This work proposes an alternative framework for parametric bioimpedance estimation as a powerful tool to characterize biological media. We model the bioimpedance as an electrical network of parallel RC circuits, and transform the frequency-domain estimation problem into a time constant domain estimation problem by means of the distribution of relaxation times (DRT) method. The Fredholm integral equation of the first kind is employed to pose the problem in a regularized least squares (RLS) form. We validate the proposed methodology by numerical simulations for a synthetic biological electrical circuit, by using a multisine signal in the frequency range of 1kHz to 853kHz and considering an error in variables (EIV) problem. Results show that the proposed method outperforms the state-of-the-art techniques for spectral bioimpedance analysis. We also illustrates its potentiality in terms of accurate spectral measurements and precise data interpretation, for further usage in biological applications. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.